Pydev debugger stopped working in PyCharm after Python upgrade

Question

I use PyCharm. I had previously built the pydev debugger under Python 3.3 using python /Applications/PyCharm.app/Contents/helpers/pydev/setup_cython.py build_ext --inplace. I then had to update my project to use a new virtual environment under Python 3.5, and now the debugger won't run, with the following message:

/<venv_path>/bin/python3.5 /Applications/PyCharm.app/Contents/helpers/pydev/pydevd.py --multiproc --save-signatures --qt-support --client 127.0.0.1 --port 58286 --file /Applications/PyCharm.app/Contents/helpers/pycharm/pytestrunner.py -p pytest_teamcity <pytest_root> <options>
Testing started at 10:25 AM ...
pydev debugger: process 94521 is connecting

Connected to pydev debugger (build 163.8233.8)
Traceback (most recent call last):
  File "/Applications/PyCharm.app/Contents/helpers/pydev/pydevd.py", line 1596, in <module>
    globals = debugger.run(setup['file'], None, None, is_module)
  File "/Applications/PyCharm.app/Contents/helpers/pydev/pydevd.py", line 956, in run
    time.sleep(0.1)  # busy wait until we receive run command
KeyboardInterrupt

I tried rerunning setup_cython.py build_ext --inplace under the updated Python version, invalidating my caches, restarting, deleting my .idea folder, but nothing manages to resolve the message above.

Answer 1

I resolved this issue by clearing all saved breakpoints.

Setting the environment variable PYCHARM_DEBUG=True in the launch lead me to this resolution.